Heavy machinery equipment is used in mining, excavation, demolition, construction, and similar activities. The parts of heavy machines which are used for digging are exposed to a great amount of wear in operation. For instance, a ground engaging tool has teeth which continually dig, rip, cut, or lift dirt, rock, concrete, metal, or other rugged materials, all of which constantly wear against and abrade the surface of the teeth.
Heavy machinery parts are expensive and time-consuming to repair or replace, so many pieces of equipment are applied with wear plates or wear structures which can be replaced more quickly. For instance, on a ripper, the tooth may be a durable cover fitted onto the end of the ripper shank, so that when the tooth wears out, the tooth is removed and replaced without the need to repair the entire ripper shank. By removing and replacing only those parts which directly engage with the ground, considerable time and expense can be saved.
However, there are many safety issues with current designs of replacement parts. For example, current designs require that a sledgehammer be used to install and remove pins which secure the replacement parts on the ripper shank. The pins are hammered into the parts, and often a tool is placed against the pin and hammered with the sledgehammer. This can lead to serious injury if the tool moves, is broken, or the sledgehammer misses its mark. For example, if hammer is swung and misses the pin, oftentimes metal chips are broken off and sent careening; those chips seriously hurt people when they hit them. The safety organizations which regulate workplace safety, such as MSHA and OSHA, disapprove of pins and replacement parts which require sledgehammers for installation. Further, a sledgehammer is also frequently used to remove the pin, by hammering the pin out of the replacement part and the ripper shank. Again, this often leads to serious injury.
Many manufacturers of such replacement parts also incorporate unique or proprietary features in the parts that make removal and replacement difficult and expensive. Some manufacturers build replacement parts with special slots that will only accommodate their own tools. Others build parts that will only accept their own replacement parts. For instance, on a ripper shank, the end of the ripper shank may be specially formed to only accept a tooth from the same manufacturer that made the ripper shank. Similarly, the tooth may have a slot or other engagement feature that requires that a proprietary pin be used to couple the tooth to the end of the ripper shank, because a slot formed between the ripper shank and the tooth will only accept those pins. Still further, some manufacturers may create coupling pins that require uniquely-shaped keys or tools to install or remove the pins.
Ripper shanks are generally made from monolithic, or one-piece, steel plates which are available in a variety of sizes and shapes up to about 170 inches. Because of the risk of injury involved in removal of a replacement part from a ripper shank with a sledgehammer, many organizations will use a cutting torch to remove the replacement part. If a torch is used, an adapter must later be welded on to the ripper shank for future use with other replacement parts. This torch cutting and welding not only takes quite a lot of time and money, but creates a weak spot on the ripper shank which is predisposed to failure during use. Ripper shanks do not alone present this problem; many other heavy machinery parts are susceptible to these issues.
Further, not only do proprietary replacement parts prove to be expensive and difficult to replace because of the manufacturer's design choices, but replacement can be hampered when the part becomes worn or damaged severely. For example, if dirt builds up in the space between the tooth and end of a ripper shank, the tooth can bind to the ripper shank and be very difficult to remove, requiring crowbars and sledgehammers to remove. If dirt clogs the socket or keyway which receives the key or tool, removal can also be difficult. An improved fastening device for coupling heavy equipment parts is needed.